kernel: cleanup the software mouse cursor mess

The swcursor used a 32x32 image for saving/restoring
screen contents for no reason.

Add a doflush argument to swcursorhide(), so that
disabling software cursor with a double buffered
softscreen is properly hidden. The doflush parameter
should be set to 0 in all other cases as swcursordraw()
will flushes both (current and previours) locations.

Make sure swcursorinit() and swcursorhide() clear the
visibility flag, even when gscreen is nil.

Remove the cursor locking and just do everything within
the drawlock. All cursor functions such as curson(),
cursoff() and setcursor() will be called drawlock
locked. This also means &cursor can be read.

Fix devmouse cursor reads and writes. We now have the
global cursor variable that is only modified under
the drawlock. So copy under drawlock.

Move the pc software cursor implementation into vgasoft
driver, so screen.c does not need to handle it as
a special case.

Remove unused functions such as drawhasclients().

1 files changed, 26 insertions, 36 deletions

diff --git a/sys/src/9/port/devmouse.c b/sys/src/9/port/devmouse.c
index e8433ef5f..940e8ef97 100644
--- a/sys/src/9/port/devmouse.c
+++ b/sys/src/9/port/devmouse.c
@@ -71,10 +71,7 @@ static Cmdtab mousectlmsg[] =
 };
 
 Mouseinfo	mouse;
-Cursorinfo	cursor;
-Cursor		curs;
 
-void	Cursortocursor(Cursor*);
 void	mouseblankscreen(int);
 int	mousechanged(void*);
 void	mouseredraw(void);
@@ -105,7 +102,7 @@ static ulong blanktime = 30;	/* in minutes; a half hour */
 
 extern Memimage* gscreen;
 
-Cursor	arrow = {
+Cursor arrow = {
 	{ -1, -1 },
 	{ 0xFF, 0xFF, 0x80, 0x01, 0x80, 0x02, 0x80, 0x0C,
 	  0x80, 0x10, 0x80, 0x10, 0x80, 0x08, 0x80, 0x04,
@@ -118,16 +115,9 @@ Cursor	arrow = {
 	  0x61, 0xF0, 0x60, 0xE0, 0x40, 0x40, 0x00, 0x00,
 	},
 };
+Cursor cursor;
 
-static void
-mousereset(void)
-{
-	if(!conf.monitor)
-		return;
-
-	curs = arrow;
-	Cursortocursor(&arrow);
-}
+static void Cursortocursor(Cursor*);
 
 static int
 mousedevgen(Chan *c, char *name, Dirtab *tab, int ntab, int i, Dir *dp)
@@ -147,12 +137,8 @@ mouseinit(void)
 {
 	if(!conf.monitor)
 		return;
-
-	curs = arrow;
-	Cursortocursor(&arrow);
-	cursoron();
 	mousetime = seconds();
-
+	Cursortocursor(&arrow);
 	kproc("mouse", mouseproc, 0);
 }
 
@@ -232,10 +218,7 @@ mouseclose(Chan *c)
 	case Qcursor:
 		if(decref(&mouse) != 0)
 			return;
-		cursoroff();
-		curs = arrow;
 		Cursortocursor(&arrow);
-		cursoron();
 	}
 }
 
@@ -246,6 +229,7 @@ mouseread(Chan *c, void *va, long n, vlong off)
 	char buf[1+4*12+1];
 	uchar *p;
 	ulong offset = off;
+	Cursor curs;
 	Mousestate m;
 	int b;
 
@@ -259,6 +243,11 @@ mouseread(Chan *c, void *va, long n, vlong off)
 			return 0;
 		if(n < 2*4+2*2*16)
 			error(Eshort);
+
+		qlock(&drawlock);
+		memmove(&curs, &cursor, sizeof(Cursor));
+		qunlock(&drawlock);
+
 		n = 2*4+2*2*16;
 		BPLONG(p+0, curs.offset.x);
 		BPLONG(p+4, curs.offset.y);
@@ -360,6 +349,7 @@ mousewrite(Chan *c, void *va, long n, vlong)
 	Point pt;
 	Cmdbuf *cb;
 	Cmdtab *ct;
+	Cursor curs;
 	char buf[64];
 	int b, z, msec;
 	Mousestate *m;
@@ -370,19 +360,16 @@ mousewrite(Chan *c, void *va, long n, vlong)
 		error(Eisdir);
 
 	case Qcursor:
-		cursoroff();
 		if(n < 2*4+2*2*16){
-			curs = arrow;
 			Cursortocursor(&arrow);
-		}else{
-			n = 2*4+2*2*16;
-			curs.offset.x = BGLONG(p+0);
-			curs.offset.y = BGLONG(p+4);
-			memmove(curs.clr, p+8, 2*16);
-			memmove(curs.set, p+40, 2*16);
-			Cursortocursor(&curs);
+			return n;
 		}
-		cursoron();
+		n = 2*4+2*2*16;
+		curs.offset.x = BGLONG(p+0);
+		curs.offset.y = BGLONG(p+4);
+		memmove(curs.clr, p+8, 2*16);
+		memmove(curs.set, p+40, 2*16);
+		Cursortocursor(&curs);
 		return n;
 
 	case Qmousectl:
@@ -498,7 +485,7 @@ Dev mousedevtab = {
 	'm',
 	"mouse",
 
-	mousereset,
+	devreset,
 	mouseinit,
 	devshutdown,
 	mouseattach,
@@ -515,14 +502,14 @@ Dev mousedevtab = {
 	devwstat,
 };
 
-void
+static void
 Cursortocursor(Cursor *c)
 {
 	qlock(&drawlock);
-	lock(&cursor);
-	memmove(&cursor.Cursor, c, sizeof(Cursor));
+	cursoroff();
+	memmove(&cursor, c, sizeof(Cursor));
 	setcursor(c);
-	unlock(&cursor);
+	cursoron();
 	qunlock(&drawlock);
 }
 
@@ -558,8 +545,11 @@ mouseproc(void*)
 	for(;;){
 		sleep(&mouse.redrawr, shouldredraw, nil);
 		mouse.redraw = 0;
+
+		qlock(&drawlock);
 		cursoroff();
 		cursoron();
+		qunlock(&drawlock);
 	}
 }